Making lead alloy castings



Feb.27,1934. E GRAF 'v 1,949,372

*MAKING LEAD ALLOY qAsTINGs Filed Feb. 29, 1932 l' er GIy SMM PatentedFeb. 27, 193% MAKING LEAD ALLOY CASTINGS Ernest Graf, Philadelphia, Pa.,assigner to The Electric Storage Battery Company, Philadelphia, Pa., acorporation of New Jersey Application February 29, 1932. Serial No.595,966

1 Claim.

Lead alloy grids and plates Afor storage batteries are examples ofintricate castings usually made in ferrous metal molds, containingintersecting mold cavities, and in making such castings it frequentlyhappens that the molten lead alloy does not flow in such a way as tofill the mold, so that'defective castings are produced. Attempts havebeen made to prolong the flow and to improve the castings by lubricatingthe 10 polished metal faces of the mold and by heating the molds.

One object of the present invention is to overcome these defects anddisadvantages and to provide for the production of perfect castingswithout the use of lubricants on the surfaces of the mold and withoutthe application of heat to the molds, or with the application of lessheat than heretofore. Another object is to give to the castings a negrained and tough structure.

Gienerally stated, the invention consists in perceptibly roughening themetal surfaces of the intersecting channels of the mold and pouring themolten lead alloy in contact with such roughened metal surfaces.

The invention also comprises the improvements to be presently describedand nally claimed.

In the practice of the invention the surfaces of the mold channels,which frequently intersect, 3Q if polished are depolished, or areotherwise made perceptibly rough, and the perceptible roughness.

of the metal mold surfaces in direct contact with the molten alloy causethe latter to flow further than it would do if in contact with polishedmetal 35 mold surfaces, or with mold surfaces lubricated of thisinvention, but in .it less heat need be applied.

The metal surface of the mold may be perceptibly Toughened or depolishedby scarifying it.

The present invention permits of the use of a relatively cold mold,While at the same time the mold is properly lled and a cold moldproduces a quick chilled casting which gives a line grained and toughstructure to the alloy.

The present invention reduces the cost of molding operations byeliminating the frequent application or renewal of the usual lubricant.

In the accompanying drawing Figure 1 is a face view illustrating partsof one-half of a well known mold for storage battery grids anddiagrammatically showing the invention.

Fig. 2 is a like view, and

Fig. 3 is an enlarged section on the line 3-3 of Fig. 1. 15

In the drawing the stipple indicates the perceptibly vroughened metallicsurfaces of the intersecting channels or cavities l, Fig. 1. and of thecavities 2, Fig. 2. 4

It will be obvious to those skilled in the art to so which the inventionrelates that modications may be made in details of construction and modeof procedure without departing from the spirit of the invention which isnot limited to such matters or otherwise than the prior art and theappended claim may require.

I claim:

For making intricate lead alloy castings, an operatively stationary moldof ferrous metal having internal intersecting channels provided with 9gmetal faces presenting perceptibily roughened metal surfaces forcontactwith the pour and which promote the progressive iiow of moltenalloy from channel to channel throughout the

